Hydroxy-alkoxylated organosilicon compounds



Unite HYDROXY-ALKOXYLATED ORGANOSILICON COMPOUNDS 2 Claims. (Cl. 260-465) This invention relates to organosiloxanes having both silicon bonded hydroxyl groups and silicon bonded alkoxy groups.

For the past several years there has been considerable progress in upgrading the properties of organic resins by incorporating therein organosilicon compositions. The first attempts at this process involve merely blending an organosilicon compound with an organic resin. It was soon found, however, that such blends suffered from serious disadvantages and ways were sought to chemically combine the organosilicon compound with the organic resin. One field which has received considerable effort has been the combining of organosilicon compounds with preformed hydroxylated alkyd resins. In general, the two most important methods involve the reaction of a monomeric silane with a hydroxylated alkyd resin or the reaction of a partially condensed siloxane with such a resin. There are other modifications of this procedure but'the one which is becoming the most accepted, particularly with respect to protective coating compositions, involves the reaction of a partially condensed siloxane with a preprepared alkyd resin.

Two variations of this method are shown in United States Patents 2,587,295 and 2,735,825. The former patent teaches the use of partially alkoxylated polysiloxanes which are free of silicon bonded hydroxyl groups. Where- 1 as these materials are adaptable for use with many types of alkyd resins it has been found that they are not universally satisfactory. For example, the alkyd has to be especially formulated for use with the alkoxylated siloxanes. Thus, a large variety of commercial alkyds are unsuitable.

The second of the above patents teaches the use of certain completely hydrolyzed organosiloxanes for reaction with alkyd resins. Completely hydrolyzed siloxanes, of course, are those which are free of silicon bonded alkoxy groups but which contain silicon bonded hydroxyl groups. It has been found that siloxanols which are free of alkoxy groups do not have as'good reactivity with preformed alkyd resins as do the siloxanes of this invention.

The applicant has discovered that by employing siloxanes having the defined amount of silicon bonded hydroxyl and the defined amount of silicon bonded alkoxyl groups infra, he is able to obtain greater reactivity with preformed alkyd resins than with siloxanes containing hydroxyl alone or alkoxyl alone. This result is most unexpected in view ofwhat has previously been known con- States Patent coming the action of organosilicon compounds with alkyd Another objectis to provide oradapted for use with epoxide resins. Other objects and advantages will be apparent from the following description.

This invention relates to organosiloxane compositions having the average empirical formula in which R is a monovalent hydrocarbon radical and in which at least 40% of the R groups are aryl hydrocarbon radicals, n has an average value from .9 to 1.4, x has an average value of from .15 to .9, R is an aliphatic hydrocarbon radical, y has an average value from .005 to .2 and in which the sum of x+y is greater than .2 and the ratio of x to y is greater than 1.

The primary advantages of this invention reside in the discovery that the above critical ratios of hydroxyl and alkoxyl to silicon give intermediates which are uniquely useful for reaction with hydroxylated organic resins. Organosiloxanes in which the ratio of organic radicals to silicon, or hydroxyl to silicon, or alkoxyl to silicon fall outside the scope of the above defined limits 1 give inferior performance with organic resins. The best resins within the scope of this invention are those in which n is from 1 to 1.2, x is from .15 to .5 and y is from .02 to .1. p

The compositions of this invention are prepared under conditions which will prevent the complete hydrolysis of depends upon (1) the amount of alcohol present during hydrolysis and (2) the solubility of the alcohol in water.

The more alcohol present during hydrolysis, the higher will be the alkoxyl content of the resin up to a point. After that, the amount of alkoxyl does not increase with additional alcohol. The less soluble the alcohol, the less is required to produce a given alkoxyl content in the finished resin.

The precise conditions necessary to produce a given alkoxyl content varies somewhat depending upon the R groups on the silicon. In general, however, all resins within the scope of this invention can be made by employing from .2 to 2 mols of alcohol per mol of silicon during the hydrolysis.

The complete hydrolysis of the alkoxy groups from the 81116011 and the complete condensation of the hydroxyl groupsis avoided by removing the water and acid fromthe reaction mixture prior to removal of the excess alcohol and solvent. When the above conditions are adhered to, products within the scope of this invention are obtained.

An alternative method of preparing the compounds of this invention is to partially hydrolyze an alkoxysilane. In general this is done by heating the silane with water in the presence of acid until the required amount of alk oxyl groups has been removed. ,The conditions during the heating should be insuflicient to cause condensation of all of the hydroxyl.

ganosilicon intermediates which can be processed to a I solvent-free state without losing an appreciable amount of reactivity toward alkyd resins. Another object is to prepare organosilicon intermediates which are especially For the purpose of this invention the siloxane can be a partially hydrolyzed, hydroxylated monoaryl hydrocarbon siloxane such as monophenylsiloxane, monotolylsiloxane or monoxenylsiloxane or mixtures and copoly- In all cases the mers of such siloxanes with any monovalent hydrocarbon substituted siloxane. Thus the siloxanes employed in this invention can be composed of various combinations of siloxane units of the type RSiO R SiO, R SiO and g. of methylamyl alcohol.

SiO In all cases the total number of hydrocarbon 5 resin solution was then stripped of solvent and volatiles by groups per silicon should be from .9 to 1.4 and at least heating up to 160 C. at 200 mm. The resulting product 40% of the total number of hydrocarbon groups should was a hard, friable solid which was a free-flowing liquid be aryl hydrocarbon radicals. at 160 C. The siloxane contained .3 silicon bonded Specific examples of R groups which can be substituted OHs per silicon and .05 methylamyloxy groups per silion the silicon are alkyl radicals such as methyl, ethyl, con. butyl and octadecyl; alkenyl groups such as vinyl, allyl This 'siloxane resin was instantly compatible with a comand hexenyl; cycloaliphatic groups such as cyclopentyl, mercial coconut oil glycerol-phthalate alkyd resin. A cyclohexyl and cyclohexenyl; aralkyl hydrocarbon groups film of the mixture was allowed to dry and it was haze such as benzyl and aryl hydrocarbon groups such as free. phenyl, tolyl, xenyl, naphthyl and anthracyl. EXAMPLE 2 For the purpose of this invention R can be any aliphatic hydrocarbon radical such as methyl, ethyl, octa- A t fi 0f mol of PheHYItPIQhIOIOSIIQHe and decyl, vinyl, ahyh hexehyh isopmpyl tertianhamYl and 2- mol of diphenyldichlorosllane was dissolved in 105 cc. ethylhexyh 7 2O 0% tlluenefand ia1dde 1i witsh5 VlgOICllS stirring to a solution The preferred compositions are those in which at least 0 met 3110 111 0 0 Water Over a Perlod 0f 40% of the R groups are phenyl and the remaining R 2 f The temperature from 14 t0 groups are lower alkyl radicals or cycloaliphatic radicals After Stlrrlhg for 8 mmutes the and-Water layer Was p Of less than 8 carbon atoms In the preferred rated, the toluene layer was refluxed to azeotrope oif the pounds is an alkyl di f less h 10 -h 2 residual water and acid, and then the remaining solvent atoms was removed by heating at 175 C. at mm. pressure. The compositions of this invention can be reacted with The t gpg g g g i; ti hi o g Q P a wide variety of hydroxylated organic compounds to give tempera ure W 3 S1 011 e ,8 P a wide variety of modified organic resins. For example, 9011 h methOXY P P h they may be reacted with polyhydric alcohols, fatty acid Thls Teslh was lmlhedla'iely Compatible With glycerides, phenol aldehyde resins, lk d resins, epoxide a commercial short coconut 011 glycerol phthalate alkyd resins or polyester resins. The alkyd resins can be either resinof the drying oil or non-drying oil type and can be either EXAMPLE 3 long or short oil resins. In general all that is necessary to react the materials of this invention with the organic The fouqwmg example shows h efiect of havmg S111 resin is to heat the two in intimate contact until compatia Con bonded alkoxyl groups slloxanebility is obtained. In general compatibility is obtained f i g z g 0f h il 1119x111 1n the tabledbezlrswg a mntudr e in a matter of a few minutes to a few hours. The result- 0 0 6113' nc P an o ing reaction products do not haze upon standing and give g zi hi Si 32 2 m t h ifi an e mix ure was en a e o wa er con arning e 12252 1 12 t i f fl i e wit h v i h iih the compositions of of isopropanol Shown the table h 1:116 this invention react with the organic resins the danger F i F were addgd over a Period of 10 Inmates dunng of gelling a batch is practically eliminated because they whlcn tune the Femperature i from 15 to 75 The become compatible before an excessive viscosity is g z g is: agltated {mnutes gffi g th reached. This means that the cost of the silicone modi- 6 aqueous am ayer was W1 fawn fied organic resins is substantially reduced and the appli- 'F h water and Hcl removed by cability of silicones in the modification of organic resins P t g? g colflcgiltratlon of the solunon was is greatly extended. lus e O 0 y welg The following examples are illustrative only and should 5 of the sPlutlon of each H3511} was mlxed wlth not be construed as limiting the invention which is prop- 5O 5 of a 45% sohftlon of the alkyd Feslns Shown belowerly delineated in the appended claims In each case the mixture was heated to 145 C. and samples were withdrawn immediately after reaching this tem- EXAMPLE 1 plelratufie an? periiorillically thereafteir. Each sample fivlvas A solution of 211.5 *g. of phenyltrichlorosilane in 99 a owe to ry. e time require to give a c ear m, cc. of toluene was added over a period of 4 minutes with 57 after the temperature had reached 145 C., is designated vigorous stirring to a mixture of 550 g. of water and 40.8 o the reactivity time in the table below.

Table Amount Reactivity time in min. with alkyd of iso- Amount resins propanol of water OH-Si OR/Si in g. g. ratio ratio Alkyd resin 1 was a non-drying short coconut oil glycerolpentaerythritol-phthalic anhydride resin.

Alkyd resin 2 was a semi-drying short soya oil glycerolphthalate resin.

Alkyd resin 3 was a. soya oil monoglyceride for use in varnishes.

resin.

5 EXAMPLE 4 A copolymer of 70 mol percent phenylsiloxane and 30 mol percent propylsiloxane containing .23 silicon bonded OH per silicon atom and .05 isopropoxy groups per silicon atom was prepared by cohydrolyzing a mixture of phenyltrichlorosilane and propyltrichlorosilane in a mixture of isopropanol and water in accordance with Example 3. After removal of all of the toluene the resin was a friable solid material which was reacted with the alkyd resins of Example 3. The reactivity time was determined in accordance with Example 3. In all cases the products were haze free.

Alkyd: Reactivity time in min. 1

EXAMPLE 5 phenylmethylsiloxane, 10 mol percent monovinylsiloxane, 5 mol percent monoxenylsiloxane and 5 mol percent SiO said copolymer containing .36 silicon bonded OH groups and .03 silicon bonded isopropoxy groups.

That which is claimed is:

1. An organosiloxane having the average empirical formula in which R is a monovalent hydrocarbon radical in which at least 40% of the R groups are aryl hydrocarbon radicals, n has an average value from .9 to 1.4, x has an average value from .15 to .9, R is an aliphatic hydrocarbon radical, y has an average value from .005 to .2 and in which the sum of x+y is greater than .2 and the ratio of x to y is greater than 1.

2. A composition in accordance with claim 1 where at least 40% of the R groups are phenyl radicals and any remaining R groups are selected from the group consisting of alkyl radicals and cycloaliphatic radicals of less than 8 carbon atoms.

References Cited in the file of this patent UNITED STATES PATENTS 2,584,344 Goodwin et al. Feb. 5, 1952 2,687,396 McLean Aug. 24, 1954 2,695,276 Hatcher Nov. 23, 1954 2,718,507 Rauner Sept. 20, 1955 2,718,508 Rauner Sept. 20, 1955 2,755,269 Moorhead July 17, 1956 

1. AN ORGANOSILOXANE HAVING THE AVERAGE EMPIRICAL FORMULA 